This invention lies in the field of high structural masts. More particularly, it is concerned with drilling masts used in the rotary drilling of deep bore holes. Still more particularly, it is concerned with a drilling mast which can be assembled in a vertical position, section by section.
In the prior art there are many types of structural masts that have been constructed for use in the oil and other industries, but most of these, if not all, are designed to be assembled on a level ground and then tilted into vertical position by lifting the top end of the mast.
This type of mast assembly requires a very long clear working area that is substantially horizontal and free of any obstacles such as trees and vegetation. In many areas of the world where drilling operations are carried on, such as in jungle or other heavily wooded areas, marshes, and other similar areas, where such clear horizontal space can be provided only at great expense, it is more convenient to transport the tower by sections or partial sections by means of helicopters into a cleared area only sufficiently large to assemble the mast in a vertical position. The problem is how to assemble the tall mast without the use of an auxiliary crane that has a boom longer than the total height of the drilling mast.